MANHEIM, Pa. -- Donald Trump questioned Hillary Clinton's loyalty to her husband on Saturday night, adding an explosive personal charge against his Democratic opponent to a turbulent week when he repeatedly veered off script.
"Hillary Clinton's only loyalty is to her financial contributors and to herself," Trump told thousands gathered in Manheim, Pennsylvania. "I don't think she's even loyal to Bill if you want to know the truth ... Why should she be, right? Why should she be?"
The extraordinary personal attack, a reference to former Bill Clinton's infidelities, came as Trump works to sharpen his focus on the economy -- and his Democratic opponent's shortcomings -- as he treks across the Midwestern battlegrounds he needs to become the 45th president of the United States.
The audience roared with approval when Trump, reading from a teleprompter, lashed out at an economic system he said was rigged against everyday Americans. Friends and foes agree he is at his best in those scripted moments.
But Trump's frequent unscripted moments are often drowning them out -- diverting attention from his economic message and alienating women and minorities with early voting already underway in some states.
He raised questions about Clinton's loyalty to her husband for the first time Saturday night. He also questioned her physical stamina, her mental health and insisted she has contempt for all Americans.
"She should be in prison," Trump declared as his supporters chanted: "Lock her up!"
Even before Saturday's remarks, the former reality television star this week fueled a self-inflicted political firestorm in a series of interviews and tweets after an underwhelming debate performance by attacking a former Miss Universe, first seizing on her weight and then calling on the world to view her "sex tape."
"He's not going to change. This is who he really is," said former Minnesota Congressman Vin Weber, a Republican. "It's ridiculous to even argue this, but if he could stay on message, which is to say if he could be somebody else, he could win."
Lifelong Republican loyalists across the country are beyond frustrated that Trump's dueling personas appear to be jeopardizing the GOP's chance to take back the White House. Despite Trump's faults, Clinton remains deeply unpopular and untrusted by a large segment of the electorate.
There is little room in the national conversation for Clinton's challenges when Trump tweets about sex tapes and questions his rival's fidelity to her husband, however.
Ohio GOP Chairman Matt Borges calls Clinton a "liar" and says she deserves to lose. "And just when it's looking like it's a good bet that she will lose, we're talking about things that I believe don't help us win," he says.
There is little sign that Trump's approach will help him expand his support beyond the white working-class voters who cram into his rallies. During Monday's opening debate, the New York billionaire said African-American voters are "living in hell." And his four-day feud with former Miss Universe Alicia Machado, a Venezuelan who is now an American citizen, threatens to push his already-low standing among women and Hispanics even lower.
The day before his Pennsylvania speech, Trump took another political risk by highlighting Clinton's role in her husband's infidelities.
"Hillary was an enabler," Trump told The New York Times on Friday. "And she attacked the women who Bill Clinton mistreated afterward. I think it's a serious problem for them, and it's something that I'm considering talking about more in the near future."
That's even as Trump's acknowledged his own marital infidelities, although he tried to draw a distinction with Bill Clinton. "I wasn't president of the United States," he told the Times when asked about his affair with Marla Maples when he was married to Ivana Trump. "I don't talk about it."
Trump veered into other areas on Saturday night that may raise questions about his temperament.
He questioned the integrity of the nation's voting system, warning supporters to keep a close eye on polling places after they vote next month -- especially in "certain areas."
"We can't lose an election because of, you know what I'm talking about," he said. "A lot of bad things happen. I don't want to lose for that reason."
Trump has repeatedly suggested that only election fraud could stop him from becoming president. There has never been evidence of widespread voting fraud in the United States.
He also suggested that organizers conspired against him at Monday night's debate. The Commission of Presidential Debates acknowledged on Friday that there was an issue with Trump's microphone, which was quieter than Clinton's at times.
"How many people in this room think maybe that was done on purpose?" Trump asked.
In the crowd of thousands, at least one Trump supporter wants him to back off the personal attacks.
"He needs to stick more to the relevant issues," said Grace Sauder, a 67-year-old retired nurse from Mountville, Penn. "It just makes him look and sound immature."
Associated Press writer Jill Colvin in Jersey City, New Jersey contributed to this report.
